#include <stdio.h> /*一个文件包含两个函数*/ 
void butler(void); /* ANSI/ISO C函数原型 */
int main (void)
{
    printf("I will summon the butler function.\n");
    bulter ();
    printf ("Yes. Bring me some tea and writeable DvDs.\n");

    return 0;
}
void bulter (void)/*函数定义的开始*/
{   
    printf("YOU rang, sir?\n");
}